Packing box



FIG. 1 is a perspective view of a packing box in accordance with the new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left and right side elevational view thereof; and,

FIG. 5 is a top and bottom plan view thereof. 

The ornamental design for packing box, as shown and described. 